1. Technical Field
The present disclosure relates to start circuits and, particularly, to a soft-start circuit for a servo motor.
2. Description of Related Art
Referring to FIG. 3, a soft-start circuit in a driver of a motor provides slow boot up for the driver of the motor. The soft-start circuit includes a resistor R0, a capacitor C0, a switch J0, and a DC power source Vdc. In charging the capacitor C0, the switch J0 is opened, and the DC power source Vdc charges the capacitor C0 via the resistor R0. When the voltage of the capacitor C0 approaches the voltage of the DC power source Vdc, the switch J0 is closed, and the DC power source Vdc charges the capacitor C0 via the switch J0. The resistor R0 slowly charges the capacitor C0. The capacitor C0 is protected from transient currents, because the current of the DC power source Vdc is limited by
      Vdc          R      ⁢                          ⁢      0        .However, the resistor R0 of the soft-start circuit is only used once during a soft-start process, thus affecting efficiency.
What is needed, therefore, is a soft-start circuit which can address the described limitations.